Initial investigation of the data confirms, as expected, that winds over the sea are markedly stronger than those over land (see Figure REF , left panel). This property is largely due to open water exerting significantly less drag on the atmosphere in contrast with the land surface, orography and man-made structures that impede strong winds. The contrast in scale over land and sea, and to a lesser extent, over low-lying and high-lying land, motivates a standardisation of wind speeds in each cell to have a common marginal distribution. In this sense, our approach is based on a copula modelling strategy over space [1]}.
